Orthotic devices are well known in the art. When a user loses partial or complete control of a muscle group, orthotic devices compensate for some or all of the missing function. When used for rehabilitation of a user having weak or absent anterior and/or posterior calf muscle group function, prior art orthotic devices may provide the user's leg with support and alignment of the user's foot and ankle as the user walks or stands.
One drawback associated with prior art orthotic devices is that they limit the motion of the joints, thereby preventing the user's foot from moving through a full or normal range of motion during ambulation. An additional drawback associated with such prior art devices is that by limiting motion of the joints, prior art orthotic devices inhibit the use of electronic stimulation of the user's muscle groups to facilitate the user moving their foot through a full range of motion. Another drawback associated with such prior art orthotic devices is that by limiting the motion of the joints, such prior art devices lead to disuse atrophy. Still another drawback associated with such prior art devices is that they maintain the user's foot in a misaligned position during ambulation. This misalignment may cause electronic stimulation of the user's muscle groups to be ineffective in assisting propulsion. It would be desirable to provide an orthotic device that held a user's foot in proper alignment, through an increased range of motion. It would also be desirable to provide an orthotic device that could be used in association with electronic stimulation of the user's muscle groups to facilitate the user moving their foot through a full range of motion.
It is known in the art to provide an orthotic device with a resilient component that stores energy as the user steps down on the device, and which returns that energy to the user's foot as the user lifts the foot off of the ground. The resiliency of such prior art devices replaces force missing from a user's missing or compromised leg muscles. Such resilient orthoses also allow a users foot to move through a wider, more normal, range of motion. One drawback associated with such prior art orthoses is that they do not stimulate the user's legs, to retrain the muscle firing of the legs to walk in a more normal gait. It would be desirable to provide a resilient orthotic device that could be used in association with electronic stimulation of the user's muscle groups to retrain the legs to walk in a more normal gait.
It is also known in the art to provide devices that electronically stimulate a user's muscle groups. Such devices apply electricity transcutaneously to anterior and/or posterior calf muscle groups to facilitate walking and standing. Generally, these devices are applied to stimulate the anterior calf muscle group, effecting toe pick up during the swing phase of a user's gait. Anterior calf group firing can be effected with electronic stimulus in the absence of an orthosis. Electrical stimulus of the posterior calf muscle group can retrain firing patterns for propulsion during the weight-bearing phase of walking. As the electrical stimulus is merely a trigger to get the user to actually fire the muscle, electrical stimulus is not optimal for training the user's posterior calf muscles to fire. Every electrical stimulus does not translate into the user actually firing the muscle. Electrical stimulus is simply too inconsistent to fire a user's posterior calf muscles sufficiently to allow for increasing propulsive speed with confidence of accident-free ambulation. Even if electrical stimulus was capable of getting the user to fire posterior calf muscles ninety percent of the time, the one time the electrical stimulus failed to get the user to fire the posterior calf muscles, the user would trip and likely fall. It would, therefore, be desirable to provide a system for electrically stimulating a user to fire posterior calf muscles without causing the user to stumble or fall.
Prior art electronic stimulation devices assist users in retraining muscle groups to fire at the appropriate time. Such devices often use the position of one leg relative to the other leg to trigger the firing of the appropriate muscle group in the leg needing assistance. While electronic stimulation devices have been shown to assist in the rehabilitation of users having weak or absent calf muscle group functions, such prior art devices also have drawbacks. One drawback associated with prior art electronic stimulation devices is in users who have developed misalignment of the joints. Electronic stimulation of posterior calf muscle function is less effective if the ankle and foot are not in proper alignment with the knee joint when electronic stimulation is applied to the calf muscle group.
Stimulation of the posterior calf muscle group while the joints are misaligned, would be of little or no effect at creating a function increase to propulsion during ambulation. If the foot is not in alignment, the propulsion from firing the muscle is ineffective at enabling the user to lengthen their step or increase their speed. This instability may also cause the user to shorten the stride of the pathological leg. Shortening the stride of the pathological leg throws off the timing of the electronic stimulus, further exacerbating instability. It would, therefore, be desirable to overcome the drawbacks associated with prior art devices and provide a resilient type orthosis which allowed for an extended range of motion for weakened or absent anterior and posterior calf muscle group function, while maintaining proper alignment of the calf and foot during rehabilitation. It would also be desirable to provide an orthosis that consistently created propulsion, retrained muscle firing patterns and increased the stability of the user's foot while standing and walking.
The difficulties encountered in the prior art discussed hereinabove are substantially eliminated by the present invention.